I have experienced going from 12 Cpu SMP to 4 CPU Numa and 4 was better though much of the improvement was most likely due to the fact we also replaced the disk farm from 150 small disks to 16 disks in an EMC unit. On the old system 2.5 hours to rebuild one index. On the new system 15 minutes. ________________________________ From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Dennis Williams Sent: Tuesday, July 18, 2006 3:28 PM To: paulastankus@xxxxxxxxx Cc: oracle-l@xxxxxxxxxxxxx Subject: Re: Oracle issue with Ultrasparc CPU's Paula, So, you are saying you went from 8 CPUs to 4 faster CPUs? In itself I could see that might cause performance to degrade. For most Oracle databases, there are many simultaneous processes. With fewer CPUs, as the server moves from process to process, there must be more CPU context switches. Having faster CPUs reduces the impact somewhat, but it might still not balance out to a net zero change in performance. Dennis Williams